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From: Helge Deller <deller@gmx.de>
To: linux-scsi@vger.kernel.org,
	James Bottomley <James.Bottomley@HansenPartnership.com>,
	linux-kernel@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Subject: [PATCH] sym53c8xx: Avoid undefined behaviour in drivers/scsi/sym53c8xx_2/sym_hipd.c:762
Date: Thu, 10 Aug 2017 21:08:49 +0200	[thread overview]
Message-ID: <20170810190849.GA12659@p100.box> (raw)

On parisc I see this UBSAN warning with a sym53c896:

 UBSAN: Undefined behaviour in ./drivers/scsi/sym53c8xx_2/sym_hipd.c:762:24
 index -1903078336 is out of range for type 'u32 [7]'

Avoid this warning by switching to dev64_ul().

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/drivers/scsi/sym53c8xx_2/sym_hipd.c b/drivers/scsi/sym53c8xx_2/sym_hipd.c
index 6b349e3..15ff285a9 100644
--- a/drivers/scsi/sym53c8xx_2/sym_hipd.c
+++ b/drivers/scsi/sym53c8xx_2/sym_hipd.c
@@ -759,7 +759,7 @@ static int sym_prepare_setting(struct Scsi_Host *shost, struct sym_hcb *np, stru
 	/*
 	 * Maximum synchronous period factor supported by the chip.
 	 */
-	period = (11 * div_10M[np->clock_divn - 1]) / (4 * np->clock_khz);
+	period = div64_ul(11 * div_10M[np->clock_divn - 1], 4 * np->clock_khz);
 	np->maxsync = period > 2540 ? 254 : period / 10;
 
 	/*

             reply	other threads:[~2017-08-10 19:08 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-10 19:08 Helge Deller [this message]
2017-08-11  7:24 ` [PATCH] sym53c8xx: Avoid undefined behaviour in drivers/scsi/sym53c8xx_2/sym_hipd.c:762 Johannes Thumshirn
2017-08-15  3:07 ` Martin K. Petersen

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